Methods :
Both eyes of 17 soft contact lens (SCL) wearers, 9 hard contact lens (HCL) wearers and 31 age- and sex-matched controls were included in this prospective study. CT and ET were measured with FD-OCT in 9 areas: corneal vertex, 4 paracentral and 4 peripheral zones in control subjects and in CL-wearers immediately after discontinuing of CL. The second measurement was performed in controls and CL-wearers after five days of CL-discontinuation. At each visit, refraction error, best-corrected visual acuity, slit-lamp examination and Schirmer test were performed in both eyes of all subjects. Statistical analyses were conducted using ANOVA, Mann-Whitney test, t-test and Wilcoxon test.

Results :
ET differed relevantly in vertex and in paracentral zones between the individual groups (HCL < SCL < controls, p<0.05) at baseline. After five days of CL restriction, an increase of ET in vertex and in paracentral zones was noted in the HCL-wearers (p<0.05), but not in the SCL-wearers and in the control group. CT did not differ relevantly between the study groups at baseline [HCL > control > SCL (p>0.05)]. Five days of contact lens restriction had no relevant influence on CT, BCVA, refraction error and Schirmer test.

Conclusions :
ET was relevantly thinner in vertex and in corneal paracentral zones in CL wearers compared to controls. A five day discontinuation of CL wearing led to an increase in ET, which was relevant in HCL-wearers.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.